A Modulation-Based Radar Target Simulator and Its Hardware Nonidealities

Abstract

Increasing demands in radar sensor performance for automotive applications require reliable test solutions for the development and verification. In this paper, a modulationbased radar target simulator suitable for automotive settings is presented. A cost-effective circuit with low complexity is proposed that modulates the radar signal directly in the E-Band without an intermediate frequency stage. Models are derived for predicting the limitations of such radar target simulators due to hardware nonidealities. The introduced radar target simulator is analyzed with respect to the derived nonidealities in order to predict its performance based on the models. As a verification, radar measurements with the target simulator are conducted, and compared with the models' predictions.

Waveform Analysis and Digital Predistortion for Modulation-Based Radar Target Simulators

“…These harmonics and intermodulations cause a deterioration of the resulting Rv-plot. A more detailed description of the influence of nonlinearities on the Rv-plot can be found in [13]. In summary, the power of the modulation signal has to be kept low to retain the mixer in its linear region for a multiplication between s mod (t) and s TX (t) with low distortions.…”

“…A modulation-based RTS, which is presented in [13], is employed in a usual application setup. The RTS is placed in front of an automotive RuT at a distance of 30 cm in an anechoic chamber.…”

“…The modulation-based RTS architecture employs a mixer to modulate the radar transmit signal. The nonlinearities of the mixer cause the modulation signal to be distorted and generate unwanted radar targets [13]. In order to decrease the influence that nonlinearities have on the simulated scenario, this paper analyzes the effects of the nonlinearities and the statistics of a typical modulation signal in order to define a required back-off.…”

Over-the-Air Calibration of mmW Imaging Radars Using Uncorrelated Continuous Wave Signals

“…The latter can be grouped to monostatic [6], [7] and bistatic radar targets [8], [9], [10]. However, they all show hardware nonidealities as described in [11]. Another approach [12], [13] shows a passive multi-target near-field calibration utilizing a synthetic-aperture-radar (SAR) imaging-like procedure.…”